To address the OP...
In my own opinion:
When I go to an Open World PvP zone, I expect to PvP...
To preform PvE actions (i.e. killing NPCs) in a PvP zone is contradictory, unsatisfying and annoying.
So if I have to pull/fight NPCs to get to my PvP goal (killing other players), its gonna get old.
Having played LotRO since open beta and being well versed in the nature of the Ettenmoors, coming to an Open World PvP map with ZERO NPCs is incredibly refreshing. I can freely fight any Imperial I find, anywhere on the map (exception of Imperial/Republic base) without thinking about...
"where is this guy gonna try to run when he starts to get low on health?"
"how close can i get before the NPCs aggro me?"
"id better not heal that guy too much that just ran into a group of NPCs to get the kb on someone who was low health, ill probably get all the aggro."
"i want to go to the ettenmoors, but no one else on my faction is out...oh i know, ill go stand in the middle of all my NPCs and watch the other side watch me"